Railway car retarders and control thereof



Feh 16, 1965 Nl cz. L.. BROWN RAILWAY CAR RETARDERS AND CONTROL E VOF 13 Sheets-Sheet l Filed May 6, 1954 NEL IN1/Emol;

BY NCL, BRQWN Hx s ATTORNEY n EDI Feb. 16, 1965 Nv. 6.7L. BROWN RAILWAY CAR RETARDERS ANucoNTRoL THEREOF 13.' Sheets-Smet 2 IN VEN TOR.

N. C. L. BROWN HIS ATTORNEY Filed May 6, 1954V Feb. 16, 1965 N. c. L. BROWN 3,169,736

RAILWAY CAR RETARDERS AND CONTROL THEREOF Filed May e, 1954 13 sheets-sheet a FIG. 5.

IN VEN TOR.

Ami/MM HIS ATTORNEY Feb. 16, 1965 N. c. l.. BRowN `RA1LwAYcAR RETARDERS AND -coN'rRoL THEREOF Filed May e, 1954 13 Sheets-Sheet 4 INVENTo NC. L. BROWN HIS ATTORNEY Feb. 16, 1965 N. c. l.. BRowN RAILWAY CAR RETARDERS AND comm. THEREOF 13 Sheets-Sheet 5 Filed May 6, 1954 INVENTOR. N. CL. BROWN HIS ATTORNEY Feb. 16, 1965 N. c. L. BROWN RAILWAY CAR RETARDERS AND CONTROL 'mam-:0F

13 Sheets-Sheet 6 Filed May 6, 1954 INVENToR. N C. L BROWN HIS ATTORNEY Feb. 16, 1965 N. c. l.. BROWN RAILWAY cAR RETARDERS AND CONTROL 'mEREoF 15 Sheets-Sheet '7 Filed May 6, 1954 HIS ATTORNEY N. C. L. BROWN RAILWAY CAR RETARDERS AND CONTROL THEREOF 13 Sheets-Sheet 8 HIS ATTORNEY Feb. 16, 1965 Filed May 6, 1954 Feb. 16, 1965 N. c. L. BROWN RAILWAY CAR RETARDERS AND CONTROL 'rHEREoF 13 Sheets-Sheet v9 Filed May 6,l 1954 HIS ATTORNEY Feb. 16, 1965 N. c. L. BROWN RAILWAY CAR RETARDERS AND coNTRoL 'rHEREoF 13` Sheets-Sheet l0 Filed May 6, 1954 IN1/Emol;

.Si @E HIS ATTORNEY IN V EN TOR.

13 Sheets-Sheet 11 HIS ATTORNEY N.C.L.BROWN Feb. 16, 1965 N. c. L. BROWN RAILWAY CAR RETABDERS AND CONTROL 'rHEREoF Filed May e, 1954 WHT om W gm N -w ...n z

Feb. 16, 1965 N. c. l.. BROWN 3,159,736

RAILWAY CAR RETARDERS AND CONTROL THEREOF Filed May 6, 1954 13' Sheets-Sheet 12 INVENTOR.

HIS ATTORNEY N.C.I BROWN Feb. 16, 1965 C.. E... BRQWN RIZEWRE REL'BBDERS MIDI CONTROL THEREOF Filed May 6, 1954i.

Emma @Rouw CAR RETARDERS RETARDER OPERATING MEcHANlsM n 15 Sheets-Sheet 13 I I I I I I I I I I I I I l I RADAR SPEED RESPONSIVE APPARATUS DETECTOR SPE E DS HIGH PAS S ELECTRONIC FILTER` I I oF ALL I i SM'PH l I FILTERI IN V EN TOR.

HIGH- PASS ELECTRONIC BMPH BY N. @.LBROWN HI S ATTORNEY "carsnupon, enteringgthe group retarders.

3,169,736 RAlLWAY CAR RETARDERS AND CQNTROL TI-IEREF Ned C. L. Brown, Scottsville,`N.Y., assignor to General Signal Corporation, a corporation of New York Filed May 6, 1954, Ser. No. 428,012

7 Claims. (Cl. 246-182).

. This invention relates to the automatic control of the speed of railway cars, and it more particularly pertains to track brake car retarders of the Weight-automatic type, and systems for governing the automatic release of pressure against the rims of Wheels of cars passing through track brake type car retarders. v l

Car retarders of the track brake typeare used primar- .ily to regulate the yspeed of: cars in hump classification yards, wherein cars and cutsl of cars are released at the crest of a hump and allowed to coast to respective classication tracks. VIn such systems the crest of the hump must be high enough for the hardest rolling and, lightest car to be able to Vcoast to the most distant vdestination in a classification track. The speed of the cars varies material- Yly because of different car Weights, 4the cars beingAV hard or easy rolling, windage, etc.y

According to the present invention, there are two stages fto which retardation is applied to cars as they progress from the hump to their respective classification tracks. The car retarders of the tirst stage are conveniently called hump retardersf. and the car retarders ofdthe second stage lare conveniently called fgroup retarders. The

hump retarders are located in the single trackleading f o of the crest offa hump, while the group |retarders are located in various branches of a yard layoutT eding -respective groups of cla'ssiication tracks. j

f Generally speaking andV without attempting tokdene detection of selected car speedsfbythe associated radar speed responsive apparatus. j v

An object of the present invention is to determine the rolling resistance of reach railway car-by. checking its acceleration or 'deceleration in travelling over apredetermined stretch of track in the progress ofthe cars from the hump to their classification tracks. i

Another objectof the present invention is to'luse the trackv/ay between the hump car retarders and the group 'car lretarders as checking f'sections for determining the rollabilityofthe carsfin accordance With'ftheir performance over this: check section of track. A

Another object of the present invention is to release 'the group Vcar retarders for car-speeds selectively determined by the performance of the cars prior toentering the group car retarders. 1

Another object of the present inventionl is to 'release -the gronpcar retardersffor car speeds selectivelyY determined by the change in speed of the. cars betweenlthe point of leaving the hump car'retarders and the point of v jen/tering the group' car retarders.

, Another object of this invention is-to retard cars'lin a l lclassiiication yardlby Weight-automatic car'retarders sub-k jectto automatic release at predetermined-speeds by speed detecting means.

y, a Weight-'automatic-car retarder havingyrelatively quickly the scope of the present invention; thecai retardersys- 'i tem according to the present invention comprises radar typespeed responsive means for each car retarder-having a directional antenna located near .the exitend .of the `associated car retarder, .and directed toward appro-aching cars, and car retarder releasing means automatically governed by the speed of the cars -to release the car retarders at predetermined car speeds; All cars are released by Vthe hump car retarders when their speed is reduced to the sanre'predetermined value, but the-release of the group car retarders is` automatically governed by the pero formance orta car in travelling from the hump retarders to the group `retarders. The radar speed detecting means is used at group retarders to indicate the speed ofthe Thus; knowing fao the car. retarder.

operated power release.` as compared td the time required 5to restore the carfretarder to its `closed position p l Anthergobiect' ofthe present invention isto provide :power driven cam releasing'means jtor -a car 'retarder wherein substantially 'greater ltra've'l Vv'of'` the cams` is required for restoration of g the. car yretarder (to a closed position as compared to the"V travelof themca'ms toirelealse l Another object of .the present invention is to provide `v'an improved cariretarder offfthe weiglztt-'auto'matic type ofrelativer rugged construction having a small number ofr I:operating parts` and linkages.

the speed at which the cars-have left the hump car retardi ersv and the/speed-,at which the carsvapproach the group car retarders, the rollabilitygor performance of each car is determined as being a car having loW,.m.edium or high rollin-g resistance. These rollability .characteristics are Vleaving the group retarders so that these cars will reach their respective destinations travelling at Vspeedsitoxprevent typical control circuit 'forgoverningjits power operation; f

FIG 4 isa modied vform of .thecar retarderaccord- `ing `toiFIG. 3 providing'for .adjustment of; thefbrake Vretarder which can have vits i rails, is supported entirely on motor operated cams dis-.

posed atoppositesides of: thetrack.v `These cams' are normally positioned for weight-automatic.,retardation of -a car entering the carretarder with control means being provided for opening the car retarders by operation of thevcams supporting the car retarders in'response to the ,Other objects,` purposes and characteristic-'features Lof the present "invention willgbe in partobvious from the accompanying xdrawinjgs and part .pointed out las the Ydescription of the invention progresses.

Indescribingthe' invention in`r detail; reference is made v to the accompanyingdrawings in.-which parts having similar functions fare 'generally identified `by similari letter :reference characters, fandin which: f Y -z-FIG. 41 `is a typical track v`layout toivvhich Ythe vpresentl embodimentsof the invention` are applied; K' y fiFIG.. 2 isa tabulationv showing group `retarder release I speeds which are employed in accordancewith cars .hav-

ing different rolling characteristics;VV

y ment ofV an improved weight-automaticcar retarderprv i. t then used-to select respective desired exit speeds'for cars FIG. 3. illustrates somewhat schematically/*ione embodi-A videdaccording to the present invention'togetherswithja FIG. 5 is a plan viewof a weight-automaticcar retarder constructed according to thepresentf'invention; FIG. 16 visan elevational sectional viewof the'cai retarder illustrated in.FIG. 5 taken H line 6 6 oiFIG. 5;

FIG. 7 is an elevational retarder, shown partly .in .line 7--7 of FIG. 5; v

. FIG. 8 is a plan view of shown partlyv `in .Patented Feb. 16, 1965v `alongafthe section f `view of the section of the car f' Vcross section, taken along theV i a portion .of `a car retarder,

s cross section, takenvalo'ngthe line '8-8 .ofFIG.-7; 'f 1 s i FIG. 9 is an elevational view, shown partly in cross section, of a portion of a car retarder taken along the line -9-9 of FIG. 5;

'^ FIG; `10 illustrates the control organization tor one embodiment of the present invention for the control of a hump` car retarder of the weight-automatic type;

' "I3-IG. 11 illustrates the organization for one embodiment lofV the present inventiontvfor'the control of a group car retarder of the weight-automatic type;

VIFIG. 12 illustrates an-organiz'ation lfor the control of hump car retarders where a plurality of gadjoining weightautomatic car retarders are employed;

of the cars passing through the retarders. These weightautomatic car retarders can be of the type illustrated, for example, in FIGS. 3, 4, 5, 6, 7, 8 and 9.

The general structure of the weight-automatic car retarder will be more readily understood with reference to the simplified and somewhat schematic view as shown in FIG. 3. I'he car retarder as illustrated in FIG. 3 com- A prises rotary cams C disposed at the opposite sides of the rios. 13A and '131s when piad side by side inusof adjoining group 'car retarders having brake shoes of .j

the spring operated t'ype :with power operated means for goveining' the degree of retardation.

=Por the Vpurpose of simplifying the illustrations and Y 'facilitating in the explanation of the invention, the variousY parts and circuits constituting the .embodiments of the invention;Y havey been shown diagrammatically and lconventional illustrations have beenfemployed', the drawings-having beenorganizedrnore with thepurpose of facilitating the understanding. of the principlesand modev` of operation of the invention than with the idea of illustrating the specific construction and larrangement of parts.

that would be employed in practice. Thel symbols (l) -and (-7-) are employed to indicate connections tothe .positive andnegative terminalsofnsuitable batteries or other` sources'of direct current and-the symbol (B+) is Lused-to indicate connection to the positive terminal of a high voltage B power supply used in the radar equipment, employed, fthe negativetermin'al of this power `plied-,being assumed to be connected nto ground. Y

With reference to FIG. 1, thetrack lay-outforwhich l the system according tothe present'.invention'isassumed f to be provide'djhas 12 *classification'tracksrwhicharefed Withlcars from ahurnp. ,Aju`nction.switch8TS is the iirst switch to be encountered by fa car progressing from the hump, and this switch isoperatedfby a suitable switch machine 8SM, A,The next track switches are lap switches -,3TS.a nd15,"lS Afor one leg of the track layout and 12TS Vanchl'tl'lS forthegother leg. These track switches are usual practice. `Beyond the lap switches, car retarders are provided which areknown as rgroup retarders, such, forexample, ascarretarders Nos. 3 and 4 which are used in braking acarif the car is4 progressing to track 1 or track 2. The track switches`2TS,`4TS, 6TS, 7TS,.9TS` andf .11TS select the particular `classificationtracksV for cars leavingthe group retarders.V 1 :According toactual practice, the

er numberof tracks, andit is'to'be understood that-the simplified yard .layoutof PIG. 1 is 'selected to facilitate the disclosure of the invention by reason vof its simplicity andthatfthel systems herein disclosedfar'e readily adaptable for use in larger track layouts; These llarger-track 'layouts generally have asvrnany as 8 classiication tracks track layoutlof a hump classication yard generally includes a much great.

operated by power switch machines SM according to the v A that'are, fed from each stretch of track including a'pair l of group car retarders such as the-car retarders'Nlos. 3

The carretarders for theV embodimentsof the invention illustrated in FIGS. 10, 11, 12 and 13 are assumed to be of theweight-'automatic type in that Ythe amount of pressure applied by'the brake shoes of the retarders is automatically adjusted in accordance with theweight track way which support the entire weight of the cars passing through the car retarder, channels CH extending transverse of the t-rackway underneath the track rails and between certain of the ties30, hook arms HA pivotally secured to the channels CH at one end, and oating levers L engaging the hook arms HA at the other end and operatively engaging shoe beams'B which in turn carry brake shoes Sv which bear against the sides of the wheels of cars passing throughthe car retarder. The oating levers Llhaverollers lwhich bear upon the tops of the cams ,C and thereby support the weight -gof the car retarder and the cars passingtherethrough. The car retarder is kept on gauge laterally by suitable bearings 32 securedto the ties 30 VVand projecting upwardly on the ties V30 between bearing -lugs` 33 which are suitably secured tothe channels ,CI-I.

To consider the structure'i'more speciiically, each of the hook arms I-IA is pivotally secured on an arcuate pad 34 at itsfinner most extremity between the track rails and the pads 34 are in the form of yokes secured to the channels CH by bolts 36. Each of the hook arms HA extends under the'vassociated track rail between two channel members CH, :and it is formed with an arcuate boss 37 in its Yupper surface, beneath the center of the rail, against whichipressure ig applied inl accordance with the pressure applied to the track rail -by `a car passing thereoyer. Hookzarms HA have upwardly extending portions 38 insideofthe'track rails engaging the-inside shoe `beams fB. Outside upwardly extendinghook `portions 39 engage the oating levers L. j Y f The floating levers Lhave upwardly extending lugs. 40 'engaginggtlie ends of the "respective outside shoe beams lB. 'Ihetloating levers L have pins 41 beneath the lugs ,'40 over vl 1ich7the hooks 39 of the hook arms are disf posed. The outer extremity of each of the 4floating levers L carriesa roller 31 which in turn rides on the uppersurface of an associated cam C in substantial vertical alignment above a shaft 42 upon whichithe cams C are rotatably secured.-V Y

The cams Care subject to simultaneous power operation,always in 'a clockwise direction, substantially onequarterof a turn being required for operation of the rollers 31 from the highest tofthe lowest bearing portion on the cams and three-quarters vof a turnv being required for operating the rollers 31" fromV the lowest portion of the 'cams C to' theirighestportion. Thus, the cams C are graduatedv down to the-lowest point 43 `substantially 90 fromlthe highest point 44. This provides for relatively quick release as compared to the three-quarters of a revolution of the cam C required to close the-car retarder.

Thus the graduation from thevlow-to high points on the Y cams Cismore gradual in' accordance with-heavier loads V:placed'on the' operating mechanism' to close the cai retarder as compared to ope-ning it.

Compression' springs V45 bearing against the opposite sides of the track rails are provided for V`'maintaining the hooks 39 of the hook armsI-IA in engagement with the pins S41 'of the oating'ileversL when there isno car -Within the c'ar, retarder.

Beforer considering `further specific structure, adjustmentsand the"like,consideration will be given as tothe relative amountsA of` pressure applied to the car wheels ascompared tothe car weights. It will bek assumed that kthe"car `wheels46 and 47 shown lin FIG. 3 carry equal weights-'andthus the wheels apply equal loads. W`1 represents the load applied to the right-hand support and W2 represents the-load applied tothe left-hand support.` It

lright hand hook arm HA to the right hand point of sup- -port on which the weight W1 is applied, R3 is the moment arm from the pin 41 to the point of application of the pressure P, and R4 represents the moment arm from the pivot pin 41 to the right hand'peint of support at which 'the Weight W1 is applied.

Since all of the parts are in equilibrium, we can take moments about the pivot point 48 wherein:

WlRg: 1

ifi/R1 Re also by moments:

. PR3=W1R4 v substituting for W1,

-thus the lever ratio is:

and P2W=IR1H42R2R3 In this manner, the desired pressure is obtained by the lengths of the moment arms being chosen to give the r desired lever ratio. It will be noted that where the hook arms HA are supported on the ties as has been assumed for the calculations, substantially half of the weightapplied to the track rail by a car is supported by the ties and thus only one quarter of the weight of the car is applied to the tops of the cams C as useful weight in applying brake shoe pressure. However, when double` rail retardation is provided, half of the Weight of thepcar is supported by the cams at oneside of the track, and thus Vtwice the pressure is applied as compared to single railV retardation. It has been found that good results can be obtained with a lever ratio of substantially 2:-1, providing a pressure of about twice the weight W applied by a car wheel. t

In practice, the car retarder according to FIG. l3 is normally closed in that the cams C are in their highest positions as shown, and with no cars in the car retarder, the channels CH rest on suitable plates 49 extending'across the ties and the brake shoes S are closed to a spacing less than the width of a car wheel.

At the entering end of the car retarder, the brakeshoes -are ared outwardly as shown in FIG. 5 for receiving a car wheel. A car wheel entering the iiaring end of the lcar retarder spreads the shoes S apart and in sodoingl raises the channels CH ott of the plates 4 9 so that the entire weight applied to the track rails is supported solely on the cams C, and braking pressure is applied tothe car retarder is self-adjusting for different width wheels in i that the channels CH are raised higher as the shoes S are spread fartherapart by the wider wheels, braking pressurefbeing applied in accordance with the lever ratio, irrespective of the wheel width.V y

Having thus considered the general construction and mode of operation of the Vweight-automatic carretarder with reference to the somewhat schematic illustration of FIG. 3, consideration will now be given toy the specic car retarder structure for an embodiment of the present invention as illustrated in FIGS. 5, 6, 7,8, and 9. For convenience in applying the description as'it. has been set forth with referenceto FIG. 3 to corresponding parts in FIGS. 5, 6, 7, 8 and v9, corresponding letter reference characters have been used to designate similar parts.

` vWith reference tothe plan View of the car retarder of FIG. 5, the car retarder comprises a plurality of shoe beams B1 of a suitable'l'ength of about 6 feet 3'inches disposed endv tov end insidefand outside of trackrailsSland 52. Suitable brakeY shoes S1 are secured to the sides of the shoe beams B1 toward the track rails 51 and 52. Although any number of shoe beams B1 can be used end torend to form a carretarder, 8 beams B1 are generally employed in end to end relationship inassociation with v each side of each of the track rails 51 and 52.

The actuation of the beams B1 in accordance with the weights of the cars is accomplished at the endsl o f the beams Bl by mechanisms extending beneath the track rails between laterally spaced ties 53 as is shown in FIG. 7. A longitudinal section through a typical onel of these mechanisms is shown in FIG. 6. With reference to FIGS. 6 and -7, the principalelements of each of these mechanisms comprises' rotary dams C1 disposed at the opposite sides of the trackwaywhich sup- `port the weight applied to the track rails, a pair of channels CHl extending underneaththe track rails and dis-VVV posed between the ties 53, a pair of hook arms HAI disposed end to end and in opposing relationship between theY channels CHI, and iioating levers L1 at the ends of the mechanism engaging the respective'hook arms HAl and operatively engaging the adjoining ends of the outside shoe beams B1. .The oating levers'Ll have rollers 54 which bear upon the tops of the cams C1 and thereby support the Weight applied to tne track rails V51V each side of the trackway by suitable connecting shafts 56 and couplings 57.

. A. car retarder operating mechanism 0M is fastened by bolts 5S to long ties 59 at one sidey of the trackway near the center of the car retarder longitudinally. This operating mechanism OM has a motor 60 coupled yto rotate the shafts 56 on the associated side of the trackway through suitable reduction gearing 6,1. Y

The shafts 56 on the opposite sides of the trackway are rotated in synchronisrn -and in the same direction by a chain 62 (see FIG. 9) extending beneath the track rails and connecting sprockets 63 which are `keyed to the shafts 56 at the respective sides of the trackway. AThe chain 62 is guarded against damage by dragging equipmentand the like by a suitable cover 64 extending underneath the track rails 5l and S2. V f Y Theshafts 55 to which the cams C1 are keyedgare journaled in U-shaped bearing brackets 65 which are supported on adjoining lties 53 and are secured to the ties by bolts 66 as is shown in FIG. 7. These bearing brackets 65 also include oppositely disposed thrust belar- Aing abutments 67 (see FIGS. 6 andS) extending upwardly from the adjoining ties 53, substantially underneath the respective track rails Sl and S2, and spaced apart a distance corresponding to the width ofv apair of channelsV CH3. having their lower webs notched out for the width of the bearing 67 as is shown in FIG. 8. Each pair of channels CHI is tied together at the bottom by guide plates 6E welded to the underside of the channels'CI-Il Vas is shown in FIG. 7 at the points where the channels 7 CI-Ilare notched out to receive the bearings 67.. Thus, each of the guide plates 68 is correspondingly notched to cooperate with the abutments 67 to prevent longitudinal and lateral movement of the channels CHI and yet permit vertical movement of the channels CHI as required in accordance with different widths of wheels, and when opening the car retarder. i Each of the guide plates 68 also has a central web 68a extending downwardly between the ties 53 and within the `Ushaped structure of the bearing support 65.

-v The hook arms HA1 are formed `as inverted channels and dispose end to end and in opposing relationship, one under each track rail, between the different pairs of channels CHL The inner ends of the hook arms HAI are supported within respective yokes 69 (see FIG. 6) extending between the channels CHl'and secured to the tops of the channels CH1 byvbolts 70. The outer ends of the hook arms HA1 have upwardly extending hooks 7i.'V

formed thereon which hook over transverse pins 72 which are formed in the floating levers L1. Y

Each of the hook arms HA has an arcuate boss 73 formed .inthe upper side thereof through which weight 'is' applied to the pressure applying mechanism. Each of the-hook arms HAI has a horizontal guide channel formed in the upper surface thereof on the inside of the associated track rail for receiving a driver 75 which is adjustable longitudinally within its channel by the piacement of shims 76 between the driverl 75 and an upwardly protruding shoulder 77a in the associated hook arm HAI.

The drivers 75 are formed with two 'laterallyY spaced upwardly extending lugs'77 engaging openings in the sate for brake shoe Wear.

. 8 FIG. .3, YbutV a modified oating lever L2 is provided wherein adjustment for wear of the brake shoes can readily be made by the tightening of the nut 83.

This iioating lever L2 is constructedin two parts, 84 and 85. The member 84 is substantially thefsame as the lever L of FIG. 3 except that it carries no roller 31, but rather the roller 31 is carried by the member SS. The linkage member' 85 is pivoted at the pivot point 86 at its left hand end in' a socket formed in the upper side of the member 84. The members iand 85 are adjustably secured together by the bolt 87 and the nut 83, the bolt 87 being dispose/d substantially normal to a. radius drawn from the pivot point'.

From this structure it will be readily apparent that the tightening of the nut 83 moves the lugs 40 of thevlever L2 closer to the track rail, and thus moves the brake shoes S in closer to the track rails as required to compen- The car retarders used in the embodiment illustrated in FIGS. 14 and 15 are of the character wherein the braking pressure is applied by springs, the pressure being adjustable by power driven means.v A suitable car retarder of thistype is disclosed, for example, 'in the U.S.

,patent to vW. K. Howe, No. 1,852,572, dated April 5, 1932.

Car retarder operating mechanisms ROM are illustrated asV being provided for, the car retarders for selectively operating the car retarders to retardation or release posiadjoining endsof inner shoe beams B1 as is shown in the plan view of FIG.`5. Similarly, the roating levers L1 are formed with two laterally spaced upwardly extending lugs 78 engaging openings in the adjoining ends of outer shoe beams B1. Y

The ends of the shoe beams B1 as well as the track rails rest on chairs 74 which arersecured to the track rails by bolts 79 as is shown -in FIG. 6. The chairs 74 also have suitable bosses securing one end of compression springs 80 (see FIG. 5), the opposite ends of which are connected in the ends of the shoe beams B1. In this manner each of the shoe beamsBl is biased outwardly from the associated track rail by the compression springs 80 at its ends. This biasing action is transmitted from the shoe beams through the lugs 77 and '778 Vof the drivers .'75 and the lioating levers L1 respectively to maintain the drivers 75 and the pins 72 of the levers L1 in close engagement with their cooperating parts of the associated hook arms HAI. l

Since the car retarder is arranged to give a degree of retardation dependent upon the Weight of a car being retarded, and since the weight of the car retarder is supported on the cams C1, this dead weight will produce retardation in addition to that produced by the weight of the cars. For example, in the case of a loaded car, the weight on a car axle may be 50,000 lbs., while with an empty car, the Weight may be inthe order of 10,000 lbs. If the dead weight of the car retarder for the length of the retarder corresponding to an axle be in the order of 6,000 lbs.,

'then the dead weight retardation adds 60% to the retardadisposed beneath the guide plates 68, which in turn are secured to the channels CHI as has been described. These springs rest on suitable plates 82 which are secured to the underside of the ties 53 by bolts 66. Y

With reference to FIG. 4, a modified form of the weight-automatic car retarder is shown wherein the general structure is as has been described with reference to tions as required. For the embodiments of the invention employing weight-automatic car retarders, the operating mechanism ROM illustrated in FIG. 3 is typical. Where the spring pressure car retarders are employed as in FIGS. 13 and 14, the car retarder mechanisms can be operated as is disclosed, for example, yin the U.S. patent yto W. K. Howe, No. 2,038,112, dated April 21, 1936.

For the embodiment of the invention illustrated in FIGS. 13 and 14, a Weighing device is used at the entrance to the first of the hump and group car retarders for determiningthedegree of retardation required for cars entering the retarders. This weighing device comprises a weighing mechanism WD (see FIGS. 14A and 15A) associated with a weighing rail WR in approach to the c ar retarder with which the Weighing device is associated. This'weighing Vrail WR is disposed in a manner to weigh the load applied to .the respective wheels on one side of the cars as the cars approach the associated car retarders, and thereby the weighing mechanism WD is actuated in accordance with the weight of cars and feeds such information to the system for use in determining the degree of retardation that may be required. The structure and organization ofthe weighing rail WR and the weighing mechanism WD may be of any suitable type, the weighing rail WR being disposed adjacent the main rail o f the trackway so that the rim of each car wheel rides up onto the Weighing rail and thereby causes actuation 'of the weighing mechanism WD. The weighing mecha common contact finger 23 and respective light weight,

medium weight and heavy weightl Contact indicating fingers 24, 25 and V26 respectively. The weighing rail WR and weighing mechanism WD may beof any suitable type, such as the type that is disclosed, for example, in the U.S. patent application of Stuart .M. Phelps, Ser. No. 386,095, filed October 14, 1953.

At the exit end of each of the car retarders is a directional antenna DA which is connected to suitable radarspeed responsive apparatus as is shown in FIGS. 10 to 15 inclusive. This radar speed responsive apparatus is assumed to vbe of the continuous wave radar type employing the Doppler frequency principle discussed in general terms in Chapter l5 of the book entitled `Radar System Engineering edited by Louis M. Ridenour and Vconstituting volume I of the Radiation Laboratory Series, published by the McGraw-Hill Book Company of New eiective.

times called an interferometer `A suitable type of interferometer for this purpose is disclosed, for example, in the U.S. application of H.y C. Kendall et al., Ser. No. 359,162, tiled June 2, 1953. n

Speed indicating relays S are provided for each interferometer for indicating dilferent speeds at which car retarder control is to be effected. `These relays are controlled through high pass electronic filters MPH which can be providedin the manner fully disclosed in the above mentioned Kendall et al. application. By this organization, each of the speed relays S becomes` picked up whenever the speed of a car being detected by this associated 4interferometer is above the speed at which conduction through the associated high pass filter MPH'becomes The Ainterferometer output governing the speed relays S can be adjusted so as to cause the speed relays to operate at different desired speeds in accordance with the requirements of Ipractice as is described in the above mentioned Kendall et al. application. v

An exit relay XR is associated with each of the interyferometers in a mannerto be picked up only upon the reception of a relatively strong signal. This occurs when a car is within substantially feet, vfor example, of the directional antenna DAtor the associated interferometer. The exit relays XR are energized through a suitable exit relay control unit of the Vinterferometer as disclosed in the above mentioned Kendall et al. application. Each exit relay has associated therewith a slow acting exit relay XP. t

A check relay CK is `associated with each of the interferometers in a manner to be picked up only in response to theinterferometer detecting the presence of a'car in motion at any speed, providedthe car hasV approached the associated car retarder thereby actuating an approach track relay ATR, or actuating the exit relay of the prior car retarder in the case of the second retarder at a double car retarder location. a

Weight relays LW,'MW and HW are provided in the system according to FIGS. 14 and 15 for, governing the degree of retardation in accordance withrthe actuation .of the associated weight detector mechanisms WD.

Having thus considered the general organization ofthe system, more detail consideration will now be given as 'tothe circuit organization upon consideration of various typical operating conditions.

oPERATIoN different release speeds are selected for 'the 'group re- `tarders as is indicated, for example, in the tabulation shown in FIG. 2. Thus, in the tabulation, itl is illustrated that ifvthe performance Vof a car is indicative of a relatively low rolling resistance, a release speed for a typical group car retarder is selected as ive miles per hour; ifa medium rolling resistance is indicated, a release speed for a typical group car retarder is selected as eight miles rper hour; and if a higher rolling resistance is indicated, it is selected thatno retardation is applied. It is to be understood that these'release speeds are arbitrary and that the'interferometers can be adjusted to provide any different speeds desired.r Itis also to be understood that adjustment of the interferometers to provide different release speeds may be made from time to time in accordance with different conditions such as changes in temperature and windage which may affect the rollability of the cars after leaving the Vgroup retarders. In considering the mode of operation of the system according to the present invention uponpassage of a car, reference will first be made to the simplified form of the inventionshown in FIGS. l0`and l1 wherein only a single car. retarder and its associated control apparatus is assumed to be provided both at the hump and at the point of entrance to the group of classication tracks.

With reference toFIG. 10, in ,order that the radar speed responsive apparatus may cause operation of the car retarder mechanism only when a car is present or in immediate approach of the car retarder, a short approach track section AT is provided in approach of the humprcar retarder (see FIG. 10) and similarly an approach track section AT1 is provided in approach of the group car retarder (see FIG. 11). Each of these Aapproach track sections provides a Aseries control circuit for picking up its associated track relay ATR Whenever the as- Vthe hump car retarder, the speed relay S-12 is picked Vup in accordance withthe detection of the speed of the car by the directionakantenna DA in combination with -the Yradar speed responsive apparatus. AvRelay S-12 is picked up through a high-pass electronic `iilter 12MPH Aas is illustrated in FIG. 10, the detail'circuit organization for the energization of a speed relay comparable to relay S-12 being fully disclosed inthe abovel mentioned The condition of the apparatus illustrated inFIGS. 10

to l5 inclusive is that which the apparatus assumes when there are no carsrwithinthe vicinity of theV car retarders.

AThe carv Vretarders are ynormally closed as selected by the associated check relays CK being in theirdropped away A positions. Thus, the hump Vcar retarder illustrated in FIG. 10, for example, is in its closedposition because energy to the Wire RET, thus calling for retardation j and closing the car retarder in Aaccordance with the energizationY of car retarder control-*circuits to be herein` after more specifically y considered with reference to FIG. s. g

'With reference to FIG. 2, atabulation is shown of the ing `a group car retardertassumingthat there is no intermediate retarders); a car of medium rolling resistance will maintainthe same spee'd,ori'ncrease its speedslightly; and a car of high rolling resistance vvill enter a group car'retarder at a speed less than the Vspeed at which itV has left the hump 'car retarder.

According to Aperformance of a vcar as described above,

k,of the closure of back Contact 29% of relay CK toV apply retarder atza speed Vabove the release speed which has been assumed VtolfbelZ miles per hour, with the car reautomatic type.

-prior-U. S. application of H. C. Kendall "et al., Ser. .No. 359,162, iled u'ne'Z, 1953-, now Patent No. 3,125,315.

Upon the picking up iofv the approach track relay ATR,-the Vcheckrrelay CK becomes picked up )byV energization from (B+) through front contact 201 of relay ATR, back Contact 2620i relay XP connected in multiple with front contact 203 of relay XR, and the lelectronic control equipment of the radar speed responsive apparatus such as is disclosed in the above mentioned `Kendall et al.

application. Relay CK when picked up fis maintained energized bya stick circuit closed at frontf contact 264 of relay CK shunting front contact Ztif'of relay-ATR just described for theipicking up ofy out ofthe circuit relay CK. u t a It 4is thus vassumed that a vcar entersthe hump car tarder closed, and with the degree ofretardation governed automatically bythe car retarder being'of the` weight- When the speed of the car has been v -reduced to the release speed of 12miles per hour, energy is applied to thefrelease car retarder control wire REL upon the dropping away of Athe lspeedrelay S-IZ'through back contact 205 of relay S-12V and back contactZ, of

relay CK. With reference to FIG. 3, it is illustrated ythat the car retarder control relay RZ 'is energized at this time bythe applicationofenergyto the release `wire REL. The circuit for the energization of relay RZ extends trom (-1-), includingback contact 205 of relay S-12, front contact 206 or relay CK, wire REL," contact 207 of a manual car retarder control level MCL, normally closed contact fingers 208 and209 of the car retarder circuit controller and winding of relay RZ, to The picking up of this relay applies energy-to the car Aretarder operating motor M through front contact 210 which operates the cams of the car retarder in a clockwise direction so that 'the rotation of the cams through approximately a quarter of a revolution provides full release of the car retarder.

As is indicated in FIG. 3, the cams 211, 212 and 213 of the car retarder circuit controller are rotatedl always in the same direction anddirectly with the release cams of the car retarder. Thus upon rotation for va quarter of a revolution in a clockwise direction, the relay RZ is deenergized by the opening of contacts 208 and 209 upon the contract pusher 214- dropping into the recess 2120i of the cam-212. Relay RZ when dropped away deenergizes the lmotor M by the opening of front contact 210 and thus stops the rotation of the carretarder cams after the car retarder has been opened to relieve pressure from the wheels of the car.

Assuming that release of the car retarder has been rendered effective after the'rear wheels of the car have cleared the approach track'circuit AT, no further retardation is applied to that car in case the speed should increase slightlyso as to cause the speed relay S-12 to again become picked up. If, however, the release becomes ef fective when the car has just entered the car retarder', an increase in speedso as to cause the speed relay S-12 to again be picked up before the rear Vwheels of the car have left the approach track circuit AT provides that the car retarder will be closed again to provide added retardation in accordance with the 4application of energy to the retardation control wire RET through'tront contact 205 of relay S-IZ, front contact 215 of relay CK, and front contact 216 of relayV ATR.

Thus, with reference to FIG. 3, the relay RZ becomes picked up to operate the motor `M to close the car retarderin accordance with the energization of a circuit extendingfromV (-1-), including front contact 205 of V relay S-12, front contact 2115 of relay CK, front Contact 216 of relay ATR, contact 217 of the manual control lever MCL, contact fingers `218 V'and 219 of the car retarder iand closes contact fingers 221 and 222. Thus energy 4is applied to themotor control relay RZ by a circuit extending from (-1-), including contact lingersv 221 and 222 `of the car'retarder-circuit controller, contact ingers 208 and 209 of the carretarder circuit controller and Winding 'of relay RZ,.to When operation is completed, contact lingers 208 and I209 open the circuit, and the contact 222 is moved to center because of pusher 229 riding on the portion 311b of theY cam 211.

If the car retarder is in its open position and a circuit has been closed calling for retardation, the initial operation of the cam'21 1 in a clockwise direction is effective to close the contact lingers 222 and 223 to thereby apply energy through the contact ngers 218 and 219 of the car retarder circuit controller to the winding of relay RZ. This energy is maintained until the car retarder is completely closed so that the pusher 220 drops into the recess 21311 of thecam 213, thus insuring full closureofl the re- Y tarder, even though the circuit initiating the closure of circuit controller which are closed at this time andwinding of relay RZ, to (j-). Y The closure of front contact 210 of relay RZ initiates operation of the motor M and'the motor drives the cams of the'car retarder in a clockwise the retarder may have been only momentarily closed.

In accordance with the progress of a car through the hump car retarder illustratedin FIG. 10 to the point of picking up the relay lXR as has ,been described, the slow acting repeater relay XP is picked up by the closure of its front contact 224. This opens a portion of the control circuit for the relay CK at back contact 202 but prior to this time the contact 203 of relay XR connected in multiple therewith is closed. As the car progresses further so that the exit relay XR becomes dropped away, upon the vrearof the car becoming out of range of the directional antenna DA, the dropping away of relay XR opens the stick circuit for relay CK at Vfront contact 203 and inas- .much as the'exit relay XP Yis picked up'at this time, the back contact 202.01. this relay is opened and thus the vcheck relay CK becomes dropped away. The dropping away of this relay closes thevback contact 200 to apply energy to the wire `RET which calls for closing of the retarder and restoration to the normal conditions that have been described as being effective when no car is present. It wil be noted that'the dropping away of relay CK opens the car retarder release circuit which has been closed to retarder, the Yradar `speed responsive apparatus senses,

accordance with the car weight.Y The circuit justV described -Y 'Inasmuch as the Vcircuit just described which closes the car retarder may be only vmomentarily closed because of the short track section AT being momentarily occupied,

it isprovided that once operation has been initiated to close theA car-retarder, the relayRZ is maintained energzed until the car retarder has reachedits fully 'closed position. This is accomplished bythe cam 211- of the carretarder circuit controller and the operation of its associated contacts. This cam is effective to cause completion of operation for either the closing or the opening of the car retarder once operation for either of these positions has been initiated. vMore specically, with the'car retarder closed las illustrated, the pusher 229 assc-ciatedV with the cam 211 maintains its associated contacts open, but if operation is initiated to open the car retarder, this pusher drops against a low surface 211a of the cam 211V i `throug'hits associated directional antenna DA1, the speed 'of Atheca r asr it approachesl the associated car retarder. Thus the radar speed responsive apparatus energizes speed relays in accordance with the speed `of-the. approaching car. If the car has relatively low rolling resistance, it has increased itsspeed to above l4 miles per hour, for example, and thusthefrequency in the radar speed responsive apparatus thatis indicatiye of `speed is above the Ycuty 'oli point cof jthe.hig h' pass electronictilters provided yin 'the control circuit of all of the speed relays S so that the relays S-'5, 'S-8, S-12land S-14 are Yall picked up. If,

however, the rolling resistance of the car is medium, .the speed is between 12 and 14 miles per hour upon approach tothegroup carn retarder illustrated in FIG. 1 1 and thus all ofthe these speedrelays are picked up except relay S-14 which requires a speed of 14 miles perhour o r greater. Furthermore, if the car approaching the group car retarder illustrated in FIG. l1 is a car of high rolling resistance, the speed of the car is below 12m'i1es per `hour and thus neither of the relays S'-12 nor S-14 is pickedup by the approachof this car.

ByV the time the car enters the approach track section ATlrso as' to pick up the associated track relay ATR1, the speed relays are conditioned in accordance with `the speed of thecar-as has been described, and the pickingup of the relay ATRI closes a'pikl up circuit yfor the check relay areefrae CKL Thus the relay 0K1 becomes picked up through front contact 225 of relay ATRl and back contact 226 of relay XPl connected in multi-ple with front contact .227 of relay XR1. This relay when picked up is maintained energized by a stick circuit including front contact 228 which shunts front contact 225 of relay ATRl out of the pick up circuit. f f

Relays S-12 and S-14 are used as selecting relays to .select the release speed at which the group car retarder yshould be opened. Inasmuch as these relays should always be indicative ofthe speed of the car as it approached the group car retarder, they are maintained energized by stick circuits dependent upon the check relayv CKI so Vthat they are maintained in their initial position until the car for which control is being provided has left the car retarder.

If vthe speed of the'car upon entering the group car retarder is above 14 miles per hour, for example, the relays S-12 and S-ld are both picked up, and upon the picking up ofy relay CKI, stick circuits are established for both'of these relays. The stick circuit for relay S-12 CFI extends from (-1-), including front contact 231 of relay S12, front contact 232 of relay CKl and lower winding of relays S-12, to The stick circuit 'for' relay S-14 extends from (-1-), including front contact 233 of relay S-14, front contact 234 of relay CK1 and lower winding of relay S-14, to If the speed of the car upon entering the group car retarder is between 12 and 14` miles per hour, relay S12 is picked up but not relay S-14, and if the car has high rolling resistance so that the `speed of the car isV below 12 miles yper hour, neither of -the relays S-12 nor S-14 is picked up upon entrance of a car rinto the group car retarder.

It the car enters the groupY car retarder which is normally closed, there is no further acceleration of the lcar because of thebraking pressure applied, and thus there can be nochange in the conditions of the relays S-12 and S-l after the carretarder has been entered.` If the car has high rolling re- .s'istance so that it has been decelerating from 12 miles per hour, it will continue to decelerate going'through the 'car retarder even ir" thecar retarder is` opened so .that

'the operation of the motor M (see FIG.V 3) according to a mode of operation that has been specilically described when considering the opening of the hump car retarder. If it is assumedv that a car of *low rolling resistance is 'being retarded by the group car retarder illustrated in FIG. l1, the relays S-12 and yS14 are both picked up at fthe time the car entersthe group car retarderk and the reylease speed relays S-S andS- are also in their picked up positions. Because of the relays S-12 and S-'14 both being picked up, it is selected that the release speedV is 5 miles per hour and that rthe speed relay S-S must 4be dropped'awayin 'order to render Vthe opening of the group carretarder eective. Thus retardation isy maintained until the relay S-Sis dropped away, andat.. this'tin1e 'energy isy applied to the car retarder release wire RELr u through front contact 235 ofrela'y CKI, yfront Contact 236 of relay 11S-.12,V vfront contact 237 of rela back vcontact 238 of relay S-S'.` l i n i If it is a car having medium rolling resistancethatis '.beingretardedby the typical group car retarder, only the relay S-12 is picked up, and thus itisiselected'that the -releasespeedfo'r the car is 8 miles per hour, and release is rendered eective in accordance with the droppingaway `of relay S-S. Upon the dropping away of @relay S-,

front contact 236 fof relay S-12, back contact 237 of relay S-lt, and back contact 239 of relay S-S.

If a car of high rolling resistance approaches the group car retarder illustrated in FIG. 1,1, the picking up ofthe check relay CKl upon entrance of the car into the approach track section AT1 applies energy to the release wire REL to immediately open the car retarder. Wire REL is energized at this time throughfront contact 235 of relay CKl and back contact 236 of relays-12.

When a group car retarder has been opened as has been described with reference to FIG. l1, it is maintained open until the car has left the car retarder unless vthe speed of the car has increased subsequent to the car retarder being opened suflciently to cause the `governing speed relay S-S or S-8`to again be picked up before the rear wheels of the car leave the approach track section AT1. More specifically, if a car of low rollinggresistance increases in speed after the car retarder has beenopened and its rear wheels `still `occupy the track section AT1, a circuit is closed to initiate the closure of the car retarder by the application of'energy to the wire RET calling for retardation through fro-nt contact 235 of relay CK1, front contact 236 of relay S-12, front contact 237 of relay S-14,

illustrated in FIG. 11, the exit relay XR1 is pickedup Y when the car approaches the directional antenna DA1 and the picking up of this relay closes a circuit at front contact 240 to cause the picking up of its slow drop away repeater relay XP1.V The stick circuit for thecheck relay CK1 is not interrupted by theopeni'ngof back Ycontact ,226 of relay XPl because the front contact 227 of relay XR1 has been closed priorto this time, but when the car has left the car retarder and movessuiciently away from the directional antenna DA1 to .permit the vdropping away of. the exit relay XR1, the relay CK'I 'becomesdropped away because its stick circuit is open at both front contact 227 of relay XR1 and back contact 226 of relay XP1. Withr the relay CKI dropped away, energy is appliedto the wire RET for the closure of; the car retarder throughvback contact 241 so that the car retarder becomes closed and normal conditionsof the organization for the control of the'group car retarder are Y l restored, all release and retardation circuits that have been :described prior to .this timebeing 'opened at front contact 235 of the check relay CK1.

FIGS. 1213A mi 13B vIn practice, `itis desirable toY provide multiple'car're- ,-tarders at the hump-and at the group locations'rather than to employ vjust single long retarders. In doing this,l v leach of the multi-ple car retarders has its own interferom- Jeter equipment;V and ycontrol apparatus` substantially -corresponding to that which has been described With-reference to FGS. lOand -ll as being associated with single l Y I Vvcar y retarders at these respective"locatior1s.;

y It will, therefore, be readilyvapparent that car-retarder No. of'FIG. -l2 is controlled -byjan organizationv similar l to that which has been specifically considered with referi vence to `lFGr. .10, and'itwilltbe.urmecessarytoredescribe the mode of operation involved; The organization for controlling car retarder No. `2` is ialsogsirnilar tothat vdescribed with reference. to FIG. lO'except that there is no ,approach track sectiorrbecause carretarder No.v 2 is imi;mediately adjoining car retarder' No. s1;y However, thec energy is applied tothe release wireREL for opening the Vcarfretarder through, front Contact 235 of relay CX11,

exit relay `1XR associated withcar retarder N051 is em-V `ployed with respect to the control of Ycar retarder No. 2 

1. IN A CAR RETARDER CONTROL SYSTEM FOR A CLASSIFICATION YARD, THE COMBINATION COMPRISING: (A) A CAR RETARDER DISPOSED AT AN INTERMEDIATE POINT IN A STRETCH OF TRACK IN A CLASSIFICATIN YARD, SAID CAR RETARDER BEING SELECTIVELY OPERABLE TO POSITIONS OF DIFFERENT DEGREES OF BRAKING AND TO A NONBRAKING POSITION, (B) WEIGHT REGISTRATION MEANS RESPONSIVE TO THE PASSAGE OF A CAR OVER A PREDETERMINED POINT ALONG SAID STRETCH OF TRACK IN ADVANCE OF SAID RETARDER FOR REGISTERING A WEIGHT CLASSIFICATION FOR SAID CAR, (C) ROLLING RESISTANCE REGISTRATION MEANS RESPONSIVE TO THE FREE ROLLING PASSAGE OF SAID CAR OVER A PREDETERMINED PORTION OF SAID TRACK IN APPROACH OF SAID RETARDER FOR REGISTERING A ROLLING CHARACTERISTIC CLASSIFICTION FOR SAID CAR, AND (D) OPERATING MEANS FOR SAID RETARDER CONTROLLED JOINTLY BY SAID WEIGTH REGISTRATION MEANS AND SAID ROLLING RESISTANCE REGISTRATION MEANS FOR FIRST OPERATING SAID RETARDER TO A DEGREE OF BRAKING IN ACCORDANCE WITH THE WEIGHT CLASSIFICATION OF SAID CAR AS REGISTERED BY SAID WEIGHT REGISTRATION MEANS AND FOR SUBSEQUENTLY OPERATING SAID RETARDER TO SAID NONBRAKING POSITION WHEN THE SPEED OF SAID CAR WITHIN THE RETARDER IS REDUCED TO A SPEED SELECTED IN ACCORDANCE WITH SAID ROLLING RESISTANCE REGISTRATION MEANS.
 7. AUTOMATIC CONTROL APPARATUS FOR A CLASSIFICATION YARD HAVING A MASTER RETARDER, ONE OR MORE GROUP RETARDERS AND ONE OR MORE STORAGE TRACKS, SAID APPARATUS COMPRISING, IN COMBINATION, MEANS FOR CONTROLLING THE SPEED OF EACH CUT LEAVING THE MASTER RETARDER OF SAID YARD TO THE SAME PRESELECTED SPEED, MEANS FOR MEASURING THE SPEED OF EACH CUT IN APPROACH TO A GROUP RETARDER, MEANS FOR COMPUTING THE ROLLING RESISTANCE FOR EACH CUT IN DEPENDENCE OF SAID PRESELECTED SPEED AND SAID MEASURED SPEED, AND MEANS FOR CONTROLLING THE SPEED OF CUTS LEAVING THE GROUP RETARDERS IN ACCORDANCE WITH THE COMPUTED ROLLING RESISTANCE OF EACH CUT. 